Railroad networks facilitate many freight delivery missions between numerous origins and destinations on a daily basis. Each delivery mission typically has a predetermined delivery route, and multiple trains are often required to share portions of track that are common to their respective delivery routes. Accordingly, railroad network administrators must schedule train traffic on the railroad network to allow each train to complete its respective delivery mission within a particular time window while minimizing downtime and preventing possible collisions with other trains. Train traffic on a railroad network is typically scheduled for a given period of time (e.g., per day) based on known quantities of freight that need to be moved from each origin to each destination. Based on this information, each train is given an estimated time of arrival (ETA) by which it should reach its destination to ensure portions of track shared with other trains will be clear at appropriate times. It is then the responsibility of train operators and/or an operating system, with the assistance of train protection signaling systems, to ensure that each train arrives at its destination by the ETA.
In general, the manner in which a train reaches its destination by the ETA is controlled by locomotive operators and/or a locomotive control system. For instance, operators may control locomotives with certain throttle and braking command strategies in order to allow the train to reach its destination by the ETA. Such command strategies often also include additional goals of optimizing certain operational aspects, such as fuel efficiency, emissions, and locomotive protection, which can affect when a train reaches its destination. And in some situations, such as when a locomotive experiences a fault that requires it to operate at reduced power levels, delays in reaching the destination may be unavoidable, which can delay the operations of other trains on the railroad network and frustrate the overall network schedule developed by the railroad network administrators.
A method of generating and executing a trip plan for a train is described in U.S. Pat. No. 8,630,757 to Daum et al. that issued on Jan. 14, 2014 (“the '757 patent”). Specifically, the method described in the '757 patent includes receiving original objectives (e.g., arrival time) from a dispatch center and communicating the original objectives to a train control system. An optimal trip plan is then generated by the train control system, whereby the train control system determines operating parameters, such as speed and power, that optimize performance factors, such as fuel consumption and emissions within the constraints of the original objectives. The train control system then generates control commands according to the trip plan to carry out a mission. During the mission, the train control system receives input indicative of current train performance capabilities, such as train health factors and whether the train is going to reach its destination by the arrival time. Based on the input, the train control system regenerates the trip plan for achieving the original objectives with optimum operating parameters in view of current performance capabilities.
While the method disclosed in the '757 patent may be somewhat effective for regenerating trip plans and control strategies for a locomotive based on performance feedback of the locomotive, it may not be optimum. For example, when a train is behind schedule, the method of the '757 patent may require train operators to manually enter delay information to be communicated to the dispatch center or to other trains on the network for recalculating their trip plans. As a result, the timeliness and accuracy of the operators input can affect the efficacy of regenerating a trip plan or changing an objective. Further, the method of the '757 patent may only addresses trip plan or objective modifications with respect to the performance of a lead locomotive or lead consist and may not account for other important aspects of train performance.
The disclosed train pacing control system is directed to overcoming one or more of the problems set forth above.